Arteriole walls have juxtaglomerular cells.

Correct Answer: A

Rationale: Juxtaglomerular (JG) cells are modified smooth muscle cells located in the walls of the afferent arterioles (and sometimes efferent) within the juxtaglomerular apparatus. They act as mechanoreceptors, releasing renin in response to low blood pressure, regulating GFR and systemic pressure. Their presence in arteriole walls is a anatomical fact, making A (True) correct.

Correct Answer: C

Rationale: The bicarbonate buffer system (HCO₃⁻/H₂CO₃) is the most important in blood, rapidly neutralizing acids or bases via CO₂ exhalation (lungs) and HCO₃⁻ regulation (kidneys). It handles ~70% of extracellular buffering. Proteins (D) and phosphate (B) contribute less, and bone (A) is a long-term reserve, making C the primary system.

Correct Answer: B

Rationale: Slurred speech and disorientation 24 hours post-head injury suggest worsening neurological status (e.g., hematoma, edema), a medical emergency. Informing the neurosurgeon (B) ensures prompt evaluation and intervention, as this exceeds routine monitoring (A) or delay (D). Preparing for surgery (C) assumes a decision not yet made, making B the critical initial action.

Correct Answer: C

Rationale: Glomerular filtration's primary function is filtering blood to form an initial filtrate (C), passing water, electrolytes, and waste into Bowman's capsule while retaining proteins and cells. Reabsorption (A) and ion transport (B) occur in tubules, and pH regulation (D) is a broader kidney role, making C the specific glomerular step.

Correct Answer: D

Rationale: Decreased albumin (A) reduces oncotic pressure, vasodilation of the afferent arteriole (B) increases glomerular pressure, and efferent vasoconstriction (C) raises it further, all boosting GFR. All are true: low albumin lessens opposition, afferent dilation enhances flow, and efferent constriction traps pressure, making E (all are correct), reassigned as D, correct.